Chx cm



Patented Aug. 15, 1950 "oYANINE DYESTUFFS John David Kendall and Frank Peter Doyle; Ilford, England, assignors to Ilford Limited,

Ilford, England, a. British company No Drawing. Application June 3, 1948, Serial No.

- 30,978. In Great Britain June 4, 1947 r This invention, relates to cyanine dyestuffs. ,In co-pending application Serial No. 30,977 dyestufi intermediates areprepared by reacting a 'cya'nine' dye of the generalFormula It eclaimsr (c1; 2e0--24o.1')

The acid HX-may be any strong acid, but the hydrohalic acids, e. g. HCl and I-IBr, and ptoluene sulphonic acid are preferred. The sol-' R1 A 2i (this being one of the resonance extremes) wherein R1 and ,Rzarethe sameor ,diflerent and are alkyl, hydroxyalkyl, aralkyl or hydroxyaralkyl groups, D1. and D2 are the same or diflerentand are residues of five-membered or six-membered ,heterocyclic nitrogen rings, n is nought or one, a: is l or 2, and A is an acid radicle, with an acid I-IX where X is the acid radicle and a trithio-orthoformate ofthe formula HC(SR3)3 where R3 is an alkyl or aralkyl group, the reaction being effected in the presence of a carboxylic acid or. anhydride which is a solvent for the reacting materials.

vent acid or anhydride is preferably a weak acid, e. g. acetic acidor acetic anhydride.

The reaction should be eifected under substantially anhydrous conditions, i. e. in the absence of any hydrolytic substance, and is best eiiected by heating the reagents together. 7

The residues D1 and D2 may be selected from the residues of thiazoles, oxazoles, selenazoles and their polycyclic homologues, such as those of the benzene, naphthalene, acenaphthene and an The product of the reaction is believed to be Q R3 II or the isomer in which the =CH -TSR3 grouping isattached to the-carbon atom of the chain which is adjacent the ring of which Dris a residue. Normally only one isomer appears to be formed. WhererD1 and D2 are thesame, the isomers will beJ-identicala- The precise location of the quaternising igrou'ps' in the "final product isindeterminate; they may be "B1 A andRz X as shown or they may be RzA and R1 X. Moreover, the anion X may replace A if the RX salts are much'less soluble. v Where R1 or R2 contains an hydroxy group this maybe acylated under the conditions of the reactionand to that extent the character 01' R1 and; R2 may differ in the product from their character in the original compound.

The groups R1 and R2 are preferably lower alkyl or hydroxyalkyl groups, e. g. methyl, ethyl or propyl groups, or the corresponding hydroxyalkyl groups, e. g. ,B-hydroxyethyl.

Since in most cases where the product is used for further condensations, such condensations will result in the removal of the SR3 group, the nature of R3 is not of special importance. For the sake of convenience, however, it may be ethyl, in which case thereagent employed is triethyl trithioorthoformate which isthemost readily obtainable compound of the series; However, it may be any other alkyl group or aralkyl group,

e, .g. tribenzyl trithio-orthoformate.

thracene series, pyridine and its polycyclic homologues, such as quinoline and a and p naphthaquinolines, lepidines, indolenines, diazines, I such as 7 pyrimidines and quinazolines, diazoles (e. g., thio-;9.;9'-diazole), oxazolines, thiazolines and selenazolines. The polycyclic compounds of this series may also be substituted in the carbocyclic rings with one or more groups such as alkyl, aryl, amino, hydroxy, alkoxy and methylene-dioxy groups, or by halogen atoms; According to the present invention trinuclear polymethine dyestufisare obtained byreacting a compound of general Formula II with a hetero cyclic nitrogen compound containing a reactive methylene group. Such compounds may be (a) compounds of the general Formula where D3 is the residue ,of a five-membered ,or

six-membered heterocyclic nitrogen compound, R4 is a hydrogen atom or a hydrocarbon group, R is an alkyl or aralkyl, hydroxyalkyl or hydroxy aralkyl group and Y is an acid radicle, and the corresponding methylene bases of the general where, Q is an oxygen atom or a sulphur atom and R6 isa hydrogen atom or a hydrocarbon group.

Though some of the products obtained where :r is one have been made by other methods, it is believed that the present invention provides for the first time a method of making those products in which a: is two, Such novel'prod Using intermediates of, type (b) iiom'pounds of type (a) which may be employed may be any of those which have been used or proposed for use in the many processes for the production of cyanine and similar dyestufis, for example, thiazoles, oxazoles, selenazoies and their polycyclic homologues such as those of the benzene, naphthalene, acenaphthene and anthracene series; pyridine and its .polycyclich'omologues such as quinoline and a and 16 naphthaquinolines; lepidines; indolenines; diazines, such as pyrimidines and quinazoline's; diazo'les (e. g. -thi0-)8;3-diazo1e); oxazolines, thiazo'lines and selenazolines. The polycyclic compounds of these series may also be substituted in the carbocyclic rings with one or more groups such as alkyl, aryl, amino, hydroxy, alkoxy and methylene-dioxy groups, or by halogenatoms.

Compounds of type (b) which may be employed are rhodanic acid and oxarlrodanic acid and the N-hydrocarbon substitution derivatives of these compounds.

The formation of the dyestufis is readily effected by heating the reagents together in solution. The solvent may be a base, e. g. pyridine, piperidine, diethylamine, triethylamine and triethanolamine, or an acid or acid anhydride, e. g. acetic acid and acetic anhydride.

- Where the dyestufi is obtained in the "form of a sulphate or an alkyl-p-tol-uene .sulphonate, it

may be converted to a salt'of another acid bytreatment with a solution of an alkali salt of such other acid, e. e. potassium chloride, otassium bromide or potassium iodide.

The following examples, in which the parts are by weight, serve to illustrate this invention:

'7 EXAMPLE 1 Preparation'of bis-2 -(3-ethyl benzthiaaoley- -y- 2'(3-ethyl benzthiazole) pentamethzne cyam'ne di-z'odz'de 1 ethylthio 2.4 dibenzthiazolyl .113-butadiene-dietho-p-toluene sulphonate (prepared as an oil from 33' diethyl thiacarbocyanine ptoluene sulphonate 2.7 parts, see application Serial 'No. 30,977, Example 3) and Z-methyl benzthiazole ethiodide (1.5 parts) were heated in anhydrous pyridine (20 '00.) for ten minutes,

The blue solution was poured into aqueous p0 tassium iodide solution, diluted with water and cooled. The washed dyestufi was recrystallised from methyl alcohol to give tiny green needles,

, 4 M. Pt. 247 (with decomposition) of the dye of the formula:

lHa I EXAMPLE 2 Preparation of 2-(3-ethyl benzthiazole)-2'-'(1- ethyl quinoline)-'y.2"(3-ethyl benzthiazole) penta'methine di iodide This was prepared as green needles, Pt.

2'36 "(with decomposition) by the general method of Example 1 by the reaction of the 'dyestufl intermediate (application Serial No. 30,9'7'7,-Example 4) with quinal-dine ethiodide.

EXAMPLE 3 Preparation-hi2 (3 ethyl-tenethtaame) -2' i3 ethyl benzmcaz' tea v.2" {3- ethyl benzthia'zole) pentamethine (ii-iodide Prepared as in Example 1, but using the dyestuff -intermediate of application Serial No, 30,971,

Example 5 and 2- metnyl bemoxazole ethiodide.

It was obtained as green crystals, M. Pt. 180

with decomposition).

EXAMPLE 4 Preparation 07 2-(3wthyi-ben2thtaaolel -2"(133- trtmethyl h indolem'neryz" {-3 ethyl benzthiazole) pentamethine cyanine cit-iodide Prepared as in Example 1 using the dyestufi intermediate of application Serial No. 30,977,

Example 21 and 1.33 trimethyl-2-methylene indolenine. It was obtained as brassy green crystals, M. 'Pt. 184 (with discomposition).

I EXAMPLE 5 i I-C2Hs \C/ II 'S Preparation of [2(3 eth'yt benei'hiazole) 5"(3- methyl 2 e tit-to '4 ice-to tetrahydrothiapol-e -"y.2 (3-ethy'Z-benzthiazole) tetramethine merocyantneltodide Prepared as Example 1 using the dyestufi 258 (with decomposition).

intermediate of applicationrSerial No. 30,977, Example 3 and 3 methyle2-thio 4-keto-tetrahydrothiazole, It was obtained as coppery green crystals, M. l=' t. 242 (with d c mposition);

EXAMPLE '1 ample 6 and 2.5-dimethyl benzthiazole ethiodide. It was obtained as green crystals, M. Pt. 248

(with decomposition) 7 EXAMPLE 9 hamlet of 2-(3-ethyl-5 -methyl benathtazole) 2 (133 trimethyl mololem'ne v.2"-

w eti tit-iodide v I is was prepared from the'dystufl intermediate of application Serial No, 30,977, Example 6 by reaction withl33-trimethy1-2-methylene dihydro indolenineiinacetic Tanhydride solution. It was isolated as in Example 1 as green crystals, 192 (with'decomposition').

(3 -'eth'yl-5 -methyl benethtazole) pentamethine 7 Preparation [2-(3-ethyl-5-methyl-benethia- 01 5!-'j- (3: methyl 29- thio 4 :lceto tetrrahydrothiazole) "/.Z"."- 3 ethyl 5 methylbenathiazole tetramethine merocyanine] iodide Prepared as in Example Lusi ng the dyestufi linteiinediate of application Serial No. 30,977, E);- ample '6 and 3-methyl-2ethio l keto-tetrahydrothiazole. Itwa-s obtained as golden crystals, M. Pt. 212 (with decomposition).

EXAMPLE 11 Preparation of [2-,(3-ethyl-5-methyl-benzthtazole) 5' (3 -1ethyl 2 thto 4 lceto tetmhydrothiae ole) 57.2" (3 ethyl 5 methylbenzthiazole) tetramethine menocyam'ne] io- Prepared as in Example 1 using the dyestuff intermediate of application Serial No. 30,977, Example 6 and 3-ethyl-2-thio-4-ketotetrahydrothiazole. It was obtained as glittering bluegreen crystals, M. Pt. 210 (with decomposition).

Preparation of '[2 (3-ethyl-5-methyl-benzthiazole) 4' (1 phenyl 3--' methyl 5 pyraeon lone) v.2" (3 ethyl 5 methyl benzthia- 4i agile) te'tr'wmethine rheroeyaniheltodtde 7 Prepared as. in Example 1 using the dyestufl intermediateof application Serial No. 30,977, Example 6 i and 1phenyl-3emethyl-5-pyrazolone. ljtwaspbtained as brownl-green crystals, M. Pt.

it Preparation arms-2"- s-em z-swillow-tenemen- 'eole) =r'y.2. (3 -fethyl-' 5- chlono benzthiaadle) penta ethme cy antrle (ii-iodide Prepared as in Example 1 using the dyestufi intermediate of application Serial N 0. 30,977, Ex-

ample v-8 and 2-methyl-5-chloro-benzthiazole ethiodide. ,It was obtained after crystallisation from a mixture. of pyridine and methyl alcohol as golden crystals, M. Pt. 260 (with decomposition). 3

EXAMPLE 14 Preparation of [2-(3-ethyl-5-chloro-benzthiazole) 5'(3 methyl 2 thto 4 ketotetrahydrothiazole) .2 (3 ethyl 5 chlorobenzthtazole) tetramethine merocyaninel iodide 1,

Prepared as in Example 1 using the dyestufl intermediate of application Serial No. 30,977,,Example 8 and 3-methyl-2-thio-4-keto-tetrahydrothiazole. lts was obtained after crystallisation from pyridineas dark green crystals, M. Pt. 210" (with decomposition) Preparation" of [2-(Si-ethyl-5-chloro-benzthia-- zole) 5f (3 ethyl 2 thto 4 keto tetrahydrothz'azole) .2" (3 ethyl 5 chlorobenzthz'aeole) tetmmethine menocyanine] ptoluene sulphonate Prepared as in Example 1 using the dyestufi intermediate of application Serial No. 30,977, Example 8' and B-ethyl-Z-thio-4-keto-tetrahydrothiazole. The dyestuff was isolated as the ptoluene sulphonate and was crystallised from methyl alcohol to give yellow-green crystals, M. Pt. 236 (with decomposition).

EXAMPLE 16 Preparation of [2(3 ethyl-5-chl ro benzthiazole) 4' (1 phenyl- 3- methyl 5 py- 'Traa'olone) 'y.2"(3"- ethyl 5 chloro b61l2- thiaeole) tetramethine merocyantnel' iodide Prepared as in Example 1 using the dyestufi intermediate of application Serial No. 30,977, Example 8 and 1 phenyl 3-methyl-5-pyrazolone.

It was obtained as brassy-green crystals, M. Pt.-

258 (with decomposition, after recrystallisation from a mixture of pyridine and methyl alcohol)'-.'"

EXAMPLEH Preparation "of-l 2-(3 ethyl 4.5 benzbenzthia-' sole) "-"5f (3 ethyl 2 thto 4 keto tetra- ""hydrothiae0le) 'y -'2"(3 ethyl 4.5 benzbenzthiaeole) tetramethtne merocyam'ne] todide l Prepared as: in Example 1 using the dyestufi intermediate of application Serial No. 30,977, Example 10 and 3-ethyl-2r-thiol-keto-tetrahydro thiazole. It was obtained after crystallisation from pyridine as magenta crystals, M. Pt. 283 (with decomposition). 1 a

Preparation of [2 -(3 ethyl 4.5 benzhenzthz'azole) 5' (3 5 methyl 2 thto 4 Iceto tetrahydrothiazolq v.2" (3 ethyl 4.5 benzvben zthiaeole) "tetramethine memcyanineJ-p toluenesulphmtate Prepared as in Example 1 using the dyestufl intermediate of application Serial No. 30,977-,Ex-'

e p e ample and 3imethyli-zthio-4-keto-tetrahy- 7 dmt-hiazolen The, dyestuffiwasjsolated asgthems .o L i toluenetsulphonate and crystallised from annixi gf P-" 't,.,. f *r n A pymzolonel .2 (1 ture of pyridineand methylalcoholxtoor ivemblueethyl qumolmey -tetmmemme memcyanimT green crystals, M. Pt. 241 (with decomposition) Q iodide v Prepared" asin Example 1" usingthedyestuff intermediate of application Serial No; 303 977; E'xample 13 and= l'-pheny1-lr-methyl ti pyrazelone.

1% It was obtained as a green powder, M. Pt: 260

(witmdeeomposition'), having the-iormulat H l C2Ha (07111 031 2H5 5 a f. NLO,

EXAMPLE 19 P k 3 a l V J U 2Q N=-CnHs.

' pun mom of [2 (3. ethyl- 4.5 benzbenzthwmoney -"y.2""(3- ethyl: 4:5 benebenzmmoze): o 5 tetmm'ethine merocya'nin'el p toluene. 'sulpho mate 24' Prepared as in Example 1. using the dyestuff intermediate of appiicati'on'Serial N0. 30,977, Example; 1D; and; 1phenyl-3-methy l;-E-pyrazolonez. It; was. obtained as; green crystals; Pt; 212

(with; decatnnosltion); having -thetfbrmular Preparation of [2- (1 -ethyl "quinoli'nel-5' ('3-ethyl 2 thto 4 ketQ -tetmhydro oxazale) 'y.2"-(1-ethzr'l qumoline) etmmethine merocuanme-l iodide Prepared; as in Exammed; usingzthe LdyesizuiE:in

termediate of application SeriaLNufiQWFhEX- I r p v p ample l3 and 3 -ethyl-2-thio,-4-keto-tetrahydro 7 "T oxazole: It'was obtained'as light g reencrystals, L (in 248, (W1th.deC0mpOS1 t1OII)".. lg figi (@THSGW 25 Preparation of bis 2; 3,--e thyL,-.beneseZenazoZei-a J; P v.2(3-ethyl-benzselenaeole) pentamethine cyf= 4Q (mine mono-ethiodidez mono-p-toluene sulphonate I 20' Prepared as in: Example 1% using the dyestufl Y I 1 "V -intermediate-ofsapplicationaSerialINo. 30337, Exgg z g ggggfgf ample: I7. and bmethylt'benzselenazole ethiodide. n The dyestuff was deposited from the pyridine e V V 7 solution; during, the heating period; Itwas, 111-. 'R epared as, intExample. 1 using: the dszestnffi tered and crystallised to givebright green crysintermediateiofapplicatiomserial Nn:t3 ,'9 ",.lilxz-- t'als; Pt: 2245" (witndeoomposition); havingthe ample: 1. and: uinaldine: ethiodidee. Itz was; okr formula: tained-asixelmwrgreen crysta1s;., 23.6? (with; 5m Se Se depnmo sitioma.

EXAMPLE 2r ocH=cHo-o Preparation of iz-(l-eethyl qumolinea-fi-(i- H ethylzg-thio 4 -I5eto tetrahgdrothiazoleh 5f: ZZmLemyL quinoline) tetmmemi 01m? (QIH1S ,O 3), g 0111; 1.

cyaninelliodideg Prepared as in Example 1 using the dyestufi I I intermediate,ofapplicationSeriaLNo, 30.977., \Ex- V p ample, Iekand: 3. ethy1T2;-thio4,keto-tetrahy drosa thiazole The dyestuff was; obtained as dark green crystals. M.. Pt. 2049 (withvdecompositionhi V 22 Preparation of [2.-(3,- ethy l -4 benzselenazole) -5- v (3 ethyZ-Z-thib-fikfit'o-tetrahydrothiazole-y v.2"-(1-ethyl qumolz'ne) te r-amethine meromemeym'mellwdzda cyanme'lbmmde Prepared, as; in; Example: 1 using the dyestuff Prepared as in Example 1 using. thedyestufi m intermediate of application Serial No. 30,977, intermediate,of'applicationserial No. 30,9.77; Ex- Example and'i 3-ethyll-2 thio l-keto-tetrahyample l4" and' 3-methyl-2 thior4rketo-tetrahy dnothi'azole. ltdwastobtained assbrown crystals; drothiazole. The dyestuff was isolated, as the Rt; 24's? (with decomposition) aiter'crystal bromide, aslighegreemcrystals, M. Pit..2-lll-'(with li'sati'on a. mixture of methyl alcohol and decompositioniar m yridine.

7 Preparation of Preparation fof yanine iii-iodide 1 Preparation 11 I EX MPLEQW 4 [2- (3 ethyl-benzselenaeo'le) (3-methyZ-2-thio-4 keto-tetrahydrothiazole) .2"(3 ethyl benzselenazole) tetramethine merocyanine] iodide I Prepared as in. Exampleal using the dyestufi intermediate of. application Serial No. 30,977,

Example, l7 and 3-methy1-2-thio-4-ket0etetraihydrothiazoleQ'Itfwas obtained as brassy-green. crystals, M. Pt. 235,(with decomposition) having the formulazt 2s :[2- (3-ethyl-benzselenazole) -4- 1 (1-phenyZ-3-methyl-5- ytazolone) .2" (3 ethyl benzselenazole) tetramethine merocyanine] iodide I Prepared as in Example '1 using the dyestuff intermediate of "application Serial No. 30,977, EX- ample -17 and 1-phenyl-3-methyl 5 pyrazo1one.

It was obtained as shiny green crystals, M; Pt. 193 (with decomposition).

EXAMPLE 29 Preparation of bis-z-(i33-trimethyl indolenine) .2 (1.3,.3-trimethyl indolenine) l eptamethine The dyestufi intermediate of applicationSerial No. 30,977, Example 18 (prepared from bis-2-(133- trimethyl *indolen'in'e) pentainethine cyanine ioidide (13 parts)) was heated WithZBB-trimethyl indolenine methiodide (7.5 parts) in acetic anhydride solution (400 parts) for five minutes.

,The solutionwasthen cooled and diluted with ether to precipitatethe dyestufi as a tar. This,

on treatment with acetone, gave a solid which was crystallised from methyl alcohol to give brown,

crystals with a red reflex, M. Pt. 238 (with decomposition) EXAMPLE 30 a 2 (3-ethyl benzthiazol'e) -2'- (133- trimethyl indolenine) 'y.2"-(l33-trimethyl indolemine) heptamethine cyanine di-iodide 1 The dye'stuff intermediate of application Serial No. 30,977, Example 18 was reacted with 2-methylbenzthiazole-ethiodide as in Example 29 to give the dyestuff as'dark brown crystals (from a mixture of methyl alcohol and pyridine), M. Pt. 214

(with decomposition) and having the formula:

on, on; 7 CH3 on;

(with decomposition) 10 EXAMPLE 31 Preparation of 2(1-ethyl auinoline) -'2'-(133-trime'thyl indolenine)--y.2" (133 trimet7iyl indolenine) heptame'thine cyanine di-iodide The dyestu'fi intermediate of application Serial No. 30,977, Example 18 was reacted with 'quinaldine ethiodide asin Example 29 to give dark blue crystals from a mixture of methyl'alcohol and pyridine, M. Pt. 213 (with decompositiom j EXAMPLESZ Preparation of [5(3-methyZ-2-thi0-4-keto-tetrai hydrothiaeole) -2- mam-methyl maoz nmer- 15-2" (1.3.3.trimethyl' N indolen'in e) hemarnethine merocyanine] iodide The dyestuftinter mediateof application seri l N 0, 30,977, Example 18 wasreacted with 3-meth'yl- '2-thio-4-keto-tetrahydrothiazole as in Example 29 heating being maintained for 30 minutes.

The dyestufi was obtained as royal blue crystals,

M. Pt. 209 (withdecomposition).

o EXAMPLE 33 Preparation of bis-2-(3-ethy l 5-methyl benzthiaz0le)-'y.2'-(3-ethyl 5-methyZ-benzthiazole) heptamethine cyanine di-iodide 1 Prepared as in Example 29 using the dyestufl intermediate, ,of application Serial No. 30,977, Example 19 and 1.6-dimethyl benzthiazole ethicdide. T The dyestuff was. isolated by pouring the acetic 'anhydride solution into hot water. It was obtained after crystallisation from a mixture of methyl alcohol and pyridine as dark' blu'e crystals,

EXAMPLE 35 Preparation of 2-(1.3,3-trimethyl indolenine)f-2 (3-ethyl5-, niethy l. benzthiaeol e) -.'y.2 (3-eth yl- 5- methyl benzthiaao le) heptamethine cyanine di-iodide Prepared as in Example 29 using the 'dyestufl "intermediate of application Serial No. 30,977,

Example 19 and 2L3.3.trimethyl' indolenine methiodi de. The dyestufi was isolated as in Example 33 to give dark green matted crystals, M. Pt. 310

- EXAMPLE 36 I ethyl-5erneth ybbenathiazole) -'y.2f (3 -cthyl' 5.

methyl-benzthiazole) heptamethine cyanine di-iodide Prepared as in Example 29 using the dyestufl intermediate of application Serial No. 30,977,

Example 19 and 2-methy1 benzoxazole ethiodide.

The dyestufi was isolated as in Example 33 to give small green crystals, M. Pt. 222 (with decomposition). I i T .Fxeparation 01 z-bi's-l2 (3:ethykii-chloro-benzthta- ;la o'Ze)-. .'=2-- (3wthylS-chloroebenzthiazole) heptamethine acyanine .dieiodide sBrepared as in Example -29 eusing athe ad-yestufl. intermediate -:of application -.Serial No. 130,917, ;Example 20 and .2-methyls5-chloro-benzthiazole :ethiodide. s'I'he dyestufi was --isolated 'faS in --Example -33 -.-to give green matted :crystals, .Pt. C10

238 (with decomposition).

EXAMPLE as r .jzxepamtio 0 :2-1Q1eethyl -quinoline)-2 :-a(3-tethylll. sehloro-bemthiazcleyz -sc3-ethyle5- chlorol ,5

'benzthiazole) heptamethinelcyanine di-rz'odi'de w Prepared as "in ,Example 29 ,using rtherdyestuff intermediate (if (application Serial -N0. T301917, Example 120 and 'qiiin'aldine rethiodi'de. The .dye-

selected from thesclassiconsisting of quaternary salts .of thev general. formula "the "same ;class "as D1 and D2, 'R is selected "from *stiffi'wasiisolatedasiin Example Bii'togivelsmallifio A L 'fiarkigreengcrystals,MiPtf2'25" '(with'ldecomposi- *tion) I "EXKMPLE 39 Preparation of 2-'-"(-1.3:3- t1imethyl indolem'ne) -2'- where R1 and Rzaare each selected from the class consisting of alkyl, hydroxyalkyl, acyloxyalkyl,

V'5-echloro-benatliiaaole) lwheptamethine cyam'ne di-ioiiide Prepared as in Example 29 using the dyestufi --groups, 1R3 sis :"seIecte'd :ffrom the "llaSS t co'nsisting 'o'f alky'l and' arallcyl 'groups, 131 and B2 are each --a :residue :01? a snu'eleus selected 'from ith'e class consisting of five-membered and sixmembered inter application Serial N 130,977: iheterocyclic .nitrogen nuclei, -n selected .irom

"Examp1'e*20 and213f3itrimethyl-indolenine=mth- Hfidiii'e. ""I'heiiyes"t1ifi" was "isolated as in .Example 'f-33 to :givediglit hlue matted Jcrystals, "M."Pt.ti214 ('withvdec'ompos'ition).

-' rWha-tme-rclaimis: Y

1. Process for Ethe production='of :.trinuclear polymethine dyestuffs which comprises reacting a compound or general -formula:

wi hers"Rp-and'fRl-z are each. selected "from thelclass 45 f'consisting or alkyl, .hydroxyalkyl, iacyloxyal-k yl, larallkyl, hydroxyaralk-yl and acyloxyaralkyl groups, R3 @is selecte'dlfrom '@the class consisting 6f alkyl and aralkyl groupsfD1 and Dzcareeach wh ere Qis selected"'frorn theitclass consisting of the oxygen atom and the sulphur atom "an'dRs %is :selected ;-from wthe class cons'isting of T the hydrogensatomcandz'hydrocarbonrigroups.

(Process according vto aclaim :1 wherein the :reaction is iefiected Eby :heating the reagents in the :p'resence O'f-Ta :base.

-:5.:Brocess according ato'aclaim :1 wherein the sreaction effected iby heating the :i ea'gents in :the ipresence of a tcarboxyli'c acid "anhydride.

%.6'. :Prot:ess :according :to xzlaim 4 wherein the a residue of a nucleus selected from the class con- 50 reautian T15 "lefiectad iby iheating B -TGHJgGHbS in sisting of five-mentlbe'red and six-membered heterocyclic nitrogen ,nuclei, n [is selected from inioughtand one,-'xfislselected "from one and -two and A and are ac d .radicles, with a hetero- "cycliccompound containing a reactivemethylene 555 group.

Process -:for' the production =1of trinuclear vipolymethine dyestuffs which momprises :reactin'g a :icompoundpf i'gene'ral; formula ofralk'yl andsaral-kyl groups, fDrzand Dz'zare teach 3-10 fa sresidue of a. :nucleus slected rfrom ith'e ICISISS consisting iof :=five -membered and 'six membered :aheterocyclic :nitrogen e'n'uclei, 3is '.-'se1ected from nought and :onepa: is L selected from one antl two and A and X are acid radicles, with a compound :75

thegpresenceiofcalbase.

'7. Process according to claim 5Whe'reinithe reaction is effected 'byiheatin'g the reagents in the presence.of.a.hase.

f8. .A ;'dyest1iff or 1 the general formula:

where R1, Raand R5 are each selected from the class consisting of alkyl, hydroxyalkyl, -'-acy1oxyalkylyaralkyl,hydroxyaralkyl and acyloxyaralkyl groups, R4 is selected from the class consisting of the hydrogen katomand hydrocarbon groups, D1, D2 and D3 are each a res due of a nucleus selected from the class consisting of five-membered and six-.membered heterocyclic nitrogen 13 .7 14 nuclei, 1: is selected from nought audience and A REFERENCES CITED and X are acid radicles.

A dye f the f ul V The fol lowmg references are of record in the S s file of thls patent:

\ 5 UNITED STATES PATENTS GCH=CHC-C V e Q v Number Name Date /N\ J N 2,385,815 Kendall Oct. 2, 1945 I I 10 FOREIGN PATENTS \s Number Country Date 549,202 Great Britain Nov. 11, 1942 JOHN DAVID EE DAIL.

FRANK PE'IER 

8. A DYESTUFF OF THE GENERAL FORMULA: 